Why do bubbles keep forming on the resin top when making coasters?

[Scott65]

I've been trying to make a set of coasters with a nice, clean resin finish, but I keep getting tiny bubbles trapped right at the surface after it cures. I tried warming the resin and using a lighter, but these little imperfections keep showing up in the final layer. Is there something I'm missing in my process to get that perfectly smooth top?

[MilaMG]

I used to get tiny surface bubbles on the coasters. I started pouring thinner layers, about 1/8 inch, and letting each layer settle a bit before the next. When bubbles show up, I pass a heat gun quickly over the surface from a few inches away to pop them, then wait a few minutes before the final layer to seal.

[Brian_M]

Humidity and dust were sneaking in for me. I wipe down the workspace, use a tack cloth, and put a clear lid over the piece between pours to stop dust from landing. I also kept the room cooler so the mix doesn’t outgas too fast.

[Matthew.R]

Do you think the bubbles are the real problem, or is the top coat picking up micro-bubbles from deeper in the pour?

[Victoria62]

I chased perfection for a while and ended up slowing down. Sometimes I just used a single, well-mixed layer and a light final coat, and still saw tiny specks, which makes me wonder if batch quality or the molds are the culprit more than technique.